Reaction force expanding and clamping device

ABSTRACT

A method of clamping and locking a roll for a steel mill on a driving pinion comprising applying a side thrust force against a roller to clamp it against a shoulder on the pinion whilst applying the reaction force produced by the side thrust force to cause a plug located in a cavity in the pinion beneath the roll to move sideways. The plug is provided with threads which when the plug is moved sideways produces a wedging action which expands the mounting surface on which the roll is mounted to lock the roll on the driving pinion.

This invention is an improvement on U.S. Pat. No. 5,700,233, U.S. Pat. 6,526,795 and U.S. Provisional Application No. 60/338,670 filed Dec. 11, 2001.

BACKGROUND OF THE INVENTION

The reduction of steel in a mill requires the presence of very robust equipment. The reduction of a steel bar to wire is usually accomplished by means of a series of reducing stands in which a pair of mating rolls are mounted on stout pinions so as to be able to exert sufficient force on a steel work product passing between the mating rolls to enable the rolls to distort the work product to a work product with a reduced cross sectional area.

It will be seen that not only do the mating rolls have to produce great force on the work product, but the rolls must produce a torque to pull the work through between the reducing rolls.

The reducing rolls are usually mounted at the end of a driving shaft (usually referred to as a pinion) in such a manner as to be able to exert substantial force in order to reduce the cross section of the work as it passes between the rolls and the pinion must transmit considerable torque from the pinion to each roll in order to pull the work between the rolls.

In order to produce an acceptable work product in which the cross section of the end work product is within an acceptable range, the rolls must be very precisely and accurately mounted on the pinion to reduce eccentricity to an acceptable value. Above all the roll must never be allowed to slip on the driving pinion (because of the possible introduction of eccentricity to the roll rotation) because of the possibility of the rejection of the resulting work product due to variations in gauge.

SUMMARY OF THE INVENTION

This invention relates to a method of mounting a reducing roll on a pinion in such a manner that the roll is tightly clamped on the pinion by the production of a compressive force on the roll (which presses the roll firmly against a shoulder on the driving pinion) whilst a simultaneous is force expands the diameter of pinion on which the roll is mounted. In this invention, the production of these two forces is interdependent, thus as the force causing the increase in diameter of the roll mounting surface of the pinion is being produced, a simultaneous reaction force is being produced which clamps the roll tightly against a shoulder on the driving pinion. An increase in one of the above forces automatically causes an increase in the other force.

PERTINENT PRIOR ART

U.S. Pat. No. 6,526,795

U.S. Pat. No. 5,700,233

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of the roll and pinion of this invention;

FIG. 2 is a perspective view of the invention of FIG. 1;

FIG. 3 is a cross sectional view of the roll and pinion of FIG. 1;

FIG. 4 is an enlargement of a section of FIG. 3;

FIG. 5 is an exploded view of the roll and pinion of FIG. 1;

FIG. 6 is a plan view of an alternative embodiment of this invention;

FIG. 7 is a sectional view of the invention illustrated in FIG. 6;

FIG. 8 is an end view of the invention of FIG. 6;

FIG. 9 is a cross sectional view of the invention shown in FIG. 8;

FIG. 10 is an enlarged detail illustration of the circled portion of FIG. 9;

FIG. 11 is a sectional perspective of the invention of FIG. 1;

FIG. 12 is an exploded view of the device of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 shows the general shape of the finished roll mounting assembly 10. The assembly 10 comprises a pinion 12 having a shoulder 14. A composite spacer assembly comprising a pair of rings 16 is mounted on pinion 12 against shoulder 14. A roll 18 is next mounted on pinion 12. A seal ring 20 is mounted on pinion 12 next to roll 18. A cap 22 is next mounted on the assembly 10.

Referring to FIG. 3 it will be necessary to describe the interior of pinion 12. Pinion 12 is provided with a hollow chamber 24 which is threaded with a buttress type thread of a very shallow slope (see U.S. Pat. No. 5,700,233). A plug 26 having a similar mating shallow buttress thread is threaded into chamber 24 as shown in FIG. 3. When plug 26 has been advanced a satisfactory distance into cavity 24, three headless bolts 28 are threaded through clearance holes 30 in plug 26 and into threaded holes 32 in pinion 12. Bolts 28 prevent plug 26 from twisting in pinion 12 once the plug 26 has reached its “home” position.

Cap 22 is now threaded on to plug 26 at threaded portion 32 (See FIG. 4). Pinion 12 is provided with an annular flange 34 which surrounds lip 36 of cap 22 with a clearance fit.

Cap 22 is provided with seal ring 38 to prevent the ingress of foreign particles such as mill scale into the assembly 10. A series of pressure bolts 40 are threaded into cap 22 at threaded holes 42. Bolts 40 are provided with seal rings 44 to prevent the ingress of foreign particles into the assembly 10.

Plug 26 is provided with shallow buttress type threads as shown in inset drawing 45.

Cap 22 is provided with a series of holes 46 which permits an operator to insert a tool therein to tighten or loosen cap 22 on the threaded end 32 of plug 26.

In operation, plug 26 is first threaded into the chamber which is provided with a surface threaded with threads 25. Plug 26 is threaded into the threaded chamber until the end of plug 26 nearly contacts the bottom of the chamber. Next bolts 28 are inserted into the clearance holes 30 provided in plug 26 and bolts 28 are subsequently tightened into threaded holes 32 provided in pinion 12. Bolts 28 prevent plug 26 from undergoing any rotational motion during operation of the assembly 10.

Next, a spacer ring assembly 16 is placed on pinion 12 against shoulder 14. Roll 18 is next mounted on pinion 12 against spacer ring assembly 16. Cap 22 carrying seal ring 38 is threaded on to plug 26 at threads 32.

When the cap 22 has been tightened on plug 26 to a predetermined torque, the tightening of pressure bolts 40 may begin. Bolts 40 are tightened in succession to: (1) clamp roll 18 against shoulder 14 of pinion 12; and (2) to cause expansion of the surface of the pinion beneath roll 18. Torquing bolts 40 will force roll 18 to move slightly to the left as shown in FIG. 3 causing plug 26 to move to the right by the reaction force produced by torquing pressure bolts 40. The reaction force produced by bolts 40 on cap 22 urges plug 26 to the right ramping the buttress threads 25 and thus expanding cavity 24. As bolts 40 are torqued to the predetermined limit, in sequence, the pinion surface beneath roll 18 is evenly expanded by the plug 26 which maintains the concentricity of roll 18 on pinion 12. At the same time, bolts 40 assure that roll 18 is held firmly in place against spacer assembly 16 which in turn abuts shoulder 14 of pinion 12.

FIGS. 6-12 show an alternative form of the invention in which the roll is clamped in the pinion assembly 110 by hydraulic pressure.

Referring to FIGS. 6-9 and FIG. 6 in particular, it will be seen that pinion assembly 110 comprises a pinion 112 on which is provided a shoulder 114 against which spacer rings 116 are located. A roll 118 is shown mounted on pinion 112. A thrust ring 120 is next shown mounted adjacent to and abutting roll 118 of assembly 110. Cap 122 is mounted adjacent thrust ring 120 of the assembly 110.

Referring now to FIGS. 7-10, it will be seen that a plug 126 (identical to previously shown plug 26) is threaded into cavity 124 of pinion 112 and bolts 128 which are threaded into holes 132 in pinion 112 to prevent plug 126 from rotating during operation of this device.

A piston plate 150 is threaded onto plug 126 at threads 133. Piston plate 150 is somewhat disc shaped and is provided with threads 133 to engage plug 126. Piston plate 150 is probably best illustrated in FIG. 12 and is provided with flange 152 (FIG. 10) to fit within flange 134 of pinion 112 (FIG. 10). Piston plate 150 is provided with a cylindraceous surface 154 which mates with the surface of the thrust ring 120 and an annular recess 156 which is provided for seal ring 158. At a larger diameter, piston plate 150 is provided with a cylindraceous surface 160 in which a sealing ring groove 162 is provided for seal ring 164.

A hydraulic fluid pressure adapter 170 is threaded into piston plate 150 at threads 172. Pressure adapter 170 is provided to the assembly 110 to provide ready connection to an external source of hydraulic pressure. An internal pressure duct 174 in adaptor 170 is shown in communication with radially extending distribution ducts 176. A pair of seal rings 178 are installed on adapter 170 at the surface which mates with piston plate 150.

Duct 174 is provided with a pair of ball checks 184 and 186 to maintain the internal pressure in the system when the external source of hydraulic pressure is removed.

Referring to FIG. 9 it will be seen that pressure release channels 180 are provided in piston plate 150 to bleed hydraulic fluid from the assembly 110. Pressure release channels 180 are normally closed by bleeder plugs 182.

It will be seen in FIGS. 7 and 9 that piston plate 150 and thrust ring 120 form an annular pressure chamber 190 which is in communication with ducts 176 and 180 bormed in piston plate 150.

Assembly and operation of this pinion assembly is as follows:

Roll 118 and spacer rings 116 are first placed on pinion 112. Plug 124 is next threaded into cavity 124 until a predetermined “home” position is reached. Headless bolts 128 are next threaded into pinion 112 to secure plug 126 against any further rotation of plug 126.

Next thrust ring 120 is fitted onto piston plate 150 and the assembly comprising piston plate 150, thrust ring 120 are threaded onto plug 126 at threads 133. Final torquing of piston plate 150 on plug 126 may be accomplished by means of hexagonal head 192 (FIG. 12) provided thereon.

When the assembly (150, 120) is in place, adapter 170 may be threaded into piston plate 150. Bleeder plugs 182 will have to be removed to permit bleeding of the assembly 110. When the unit is ready for pressurization bleeder plugs 182 are replaced.

A source of external hydraulic pressure is applied to adaptor 170. This pressure is applied to chamber 190 by means of ducts 174 and 176. As soon as chamber 190 becomes pressurized, thrust ring 120 is forced to the left whilst the reaction force which is applied to piston plate 150 tends to pull the plug 126 to the right. As with the previous version of this assembly, these two forces are equal and opposite. When a predetermined pressure is reached in chamber 190, the pressure source is removed from adaptor 170 (ball checks 184 and 186 maintain the pressure) and cap 122 is installed on pressure plate 150 at threads 192.

When it is desired to remove roll 118 from the pinion assembly 110, cap 122 is unscrewed from piston plate 150 and one or all bleeder plugs 182 are removed from piston plate 150 to release the hydraulic pressure in chamber 190.

The piston plate 150, thrust collar 120 assembly is next removed by unscrewing piston plate 150 from plug 126 and it will be seen that the roll mounting surface of pinion 112 will have contracted sufficiently that the roll may be easily removed from pinion 112. 

1. An assembly for mounting and clamping a roll on a pinion comprising: a pinion having a shoulder provided thereon adjacent a roll mounting surface on said pinion; said pinion being provided with a hollow cylindraceous cavity immediately below said roll mounting surface, said cylindraceous cavity being threaded with a shallow buttress type thread of a predetermined profile; plug means being threaded into said cavity a predetermined distance, said plug means being provided with matching type buttress threads corresponding to said threads provided in said cavity; force means for producing a first force in a transmission member to force said roll against said shoulder; said force means also producing a second force which is equal and opposite to said first force; said second force being applied to said plug means to cause axial movement of said plug means in said cavity said plug being moved axially in a direction opposite to said first force a sufficient distance to expand said roll mounting surface.
 2. A method of clamping and locking a roll on a pinion comprising: providing a pinion with a surface suitable for mounting a roll thereon; providing said pinion with a shoulder having an annular surface thereon for mounting a roll against said shoulder on said pinion; providing a roll for mounting on said pinion; providing a cylindraceous cavity beneath said mounting surface a predetermined distance, providing a shallow sloped buttress thread of a predetermined configuration on the interior surface of said cavity; providing a threaded plug to engage the shallow buttress threads of said cavity; a first force producing means engaging said roll to force said roll against said shoulder; a reaction force produced in said force producing means applied to said plug to cause lateral motion of said plug in said cavity to ramp the buttress threads so as to simultaneously expand said cavity as said force is being applied to said roll.
 3. An assembly for mounting and clamping a roll on the end of a pinion comprising: a pinion having a roller mounting surface provided thereon and wherein said pinion is provided with a roll engaging shoulder adjacent said roll mounting surface, said pinion being provided with a hollow cylindraceous cavity located immediately below said roll mounting surface, said cylindraceous cavity being threaded with a shallow buttress thread of a predetermined profile, plug means being provided with matching buttress threads threaded into said cavity a predetermined distance, lock mans for said plug means to prevent further rotation of said plug means once said predetermined distance is reached, first force means being produced in said assembly for forcing said roll against said shoulder, and reaction force being produced by said first force means for moving said plug means laterally to cause ramping of said buttress threads, to cause said cavity to expand beneath said roll.
 4. An assembly as claimed in claim 1 wherein said lock means comprises at least one bolt passing freely through said plug means and secured to said cavity.
 5. An assembly as claimed in claim 2 wherein said first force means comprises a series of compression bolts threaded into a collar which engage said roll, said collar being attached to said plug means so that when said compression bolts are torqued, a reaction force is produced in said plug means moving said plug means laterally and causing ramping of said threads.
 6. An assembly as claimed in claim 2 wherein said first force means comprises a fluid pressure force forcing said roll against said shoulder, and a reaction fluid force simultaneously producing an equal and opposite force on said plug means causing lateral movement of said plug to ramp said threads and expand said cavity beneath said roll. 